Commissioner Frederick H. Bealefeld III, left, has brought Grayling G. Williams, right, a former counternarcotics chief in the Department of Homeland Security, to lead an anticorruption division in Baltimore’s Police Department.Credit
Matt Roth for The New York Times

BALTIMORE — Tucked behind a liquor store, opposite a flooring company, Majestic Body Shop was an unremarkable sight amid a blur of commercial properties just east of the city limits. But the police cars that always seemed to be parked at the repair shop caught the eyes of passing drivers. The F.B.I. noticed as well — agents were videotaping Majestic and tapping its phone.

What the investigation revealed was startling: a bribery racket suspected to involve kickbacks to dozens of Baltimore police officers.

The scheme to divert cars damaged in traffic accidents to the body shop in return for payoffs resulted in one of the widest police corruption scandals in Baltimore history. This week, a 10th officer will be sentenced to prison, one of 14 officers who pleaded guilty to federal extortion charges. One trial ended in conviction, another officer pleaded guilty in state court and at least 14 suspended officers still face departmental discipline and possible state charges.

The scandal delivered a body blow to a police force that has struggled to win public confidence. The sheer number of officers involved stunned department veterans and civilians alike.

In the aftermath, Commissioner Frederick H. Bealefeld III — who invited the F.B.I. to investigate the force — brought in Grayling G. Williams, the Department of Homeland Security’s former counternarcotics chief, to head the division charged with rooting out corruption. The previous director had been ousted for socializing with an officer indicted on a charge of heroin trafficking. “We want to do a better job,” Mr. Williams said, “and we want this to be the Police Department that the public wants.”

Mr. Bealefeld, 49, who recently announced plans to retire in August after 31 years on the force, will almost certainly be remembered for reducing the city’s crime and murder rates as well as for his aggressive anticorruption efforts, including the Majestic case. He acknowledged that the corruption cases during his five years as commissioner had been trying, but said “it comes with the territory.”

And he made no apologies for his efforts to change the department’s direction and shed its troubled image reinforced — unfairly, Mr. Bealefeld contended — by the fictional television drama “The Wire.”

“I made clear from the very beginning that I would hold bad cops accountable,” he said.

The Baltimore case was unusual for the large number of officers involved; police corruption typically involves only a small number of officers.

Mr. Williams was picked to lead the anticorruption division in the aftermath of a kickback scheme involving a body shop.Credit
Kim Hairston/The Baltimore Sun

The scheme began when Officer Jhonn S. Corona struck a deal to bring business to two brothers, Hernan Moreno Mejia and Edwin Mejia, the body shop’s owners. All three have pleaded guilty; Mr. Corona received a sentence of two and a half years last month.

The plan worked like this: Officers who summon a tow truck to accident scenes are required to use so-called medallion tow trucks authorized by the city; instead, they would call the Mejia brothers, who would send a nonmedallion truck.

Each time a car reached Majestic, officers received several hundred dollars. Some damaged the cars more to increase the insurance payout. The scheme grew as Mr. Corona recruited other officers, who in turn brought in more colleagues, until at least 51 were involved. Court documents from one defendant suggest 59 officers made calls to the brothers.

Even before the Majestic case came to light, Mr. Bealefeld had worried that internal oversight was failing and had turned to the F.B.I. because of rumors of criminality on the force, including the officer who was eventually indicted on a charge of dealing heroin.

The turning point came after Paula Protani, an employee of a medallion towing company and the vice president of a towing association, filed a complaint in August 2009 that the police passed to the F.B.I. The agency began recording calls between the brothers and officers. Bank records revealed that the brothers paid between $200,000 and $1 million to the officers.

“It was quick, easy money in their pockets,” Ms. Protani said.

As the operation continued, the scope of the graft took shape. Rather than play down the case, Mr. Bealefeld sought to make an example of the officers.

When the time came last year to make arrests in the case, Mr. Bealefeld and federal agents lured the 17 officers facing federal charges to the police academy, where Mr. Bealefeld confronted them and stripped them of their badges before agents led them away in handcuffs. To ensure that future officers knew about it, he summoned two academy recruits to watch.

The commissioner has been aggressive in his efforts to mend the department’s reputation, said Rod J. Rosenstein, the United States attorney for Maryland.

“He knows that there has been a problem,” Mr. Rosenstein said. “He’s personally committed to doing everything he can to hold accountable corrupt police officers in order to change the culture of the organization.”

Mayor Stephanie Rawlings-Blake, whose predecessor stepped down in a plea deal related to corruption, said the Majestic case had been a “double-edged sword,” revealing graft to prove that the city did not sweep it under the rug.

“I understand the risks in all of that,” she said, “but I know that in the long run, it’s the best thing for the city.”

A version of this article appears in print on May 9, 2012, on page A11 of the New York edition with the headline: Baltimore Police Scandal Spotlights Leader’s Fight To Root Out Corruption. Order Reprints|Today's Paper|Subscribe